I switched to NTSC signal. I think it’s much simpler and easier, but it’s monochrome.
I’ve managed to get around 40 pixels width and working to increase vertical resolution.
It’s a very good idea to use constant length of interrupt to send NTSC signal apart from your pixel manipulation.

It just counts 0 to 9 with 7-segment LED. Only digit 1 side has been used since the digit 2 is burned out…
Adjust output pins for your environment. For simplicity, you need 7 pins for output in this example.
I am sure I can reduce the number of pins with demux. That’s gonna be the next project.